Clock

ABSTRACT

A clock has a clockwork movement enclosed in a soundproof case of expanded plastic material having a substantially non-porous smooth outer surface and a sponge-like inner cellular structure. The dial and hands and, possibly, a sonorous alarm are located outside the case.

United States Patent 11 1 Nava et al. 1 1 May 29, 1973 CLOCK 175] Inventors: Riccardo Giuseppe Nava; Giorgio [56] References cued v Augusto llomani; Duccio Riccardo UNITED STATES PATENTS SoffientIm; Aldo Rodolfo Subert; 4 Alessandro Giuseppe Ube -ta zi; 1,907,282 5/1933 Waldheim ..58/53 X Peter Roman Vetter, a of Milan 1,907,310 5/1933 Waldheim ..58/53 x Ital 2,012,002 8/1935 Finch ..58/55 y 2,491,453 12/1949 Knobel ..58/53 X Assignee: Cohel-Compagnie dHorlogerie et Electronique SA, Roveredo, Switzerland Filed: May 31, 1972 Appl. No.: 258,414

Foreign Application Priority Data July 5, l97l Switzerland ..9875/71 US. Cl ..58/53, 58/55 Int. Cl. G04b 37/00 Field of Search Primary ExaminerRichard B. Wilkinson Assistant Exarr'zinerLawrence R. Franklin Atl0rneyRobert E. Burns and Emmanuel J. Lobato [57] ABSTRACT A clock has a clockwork movement enclosed in a soundproof case of expanded plastic material having a substantially non-porous smooth outer surface and a sponge-like inner cellular structure. The dial and hands and, possibly, a sonorous alarm are located outside the case.

4 Claims, 1 Drawing Figure CLOCK BACKGROUND OF THE INVENTION This invention relates to clocks, and is particularly concerned with soundproof clocks in which the noise of a mechanical clockwork movement is rendered inaudible.

It has already been proposed in U.S. Pat. No. 1,345,766 to provide, in a clock, in combination with a main frame which encloses and carries the clockwork movement, a substantially soundproof sub-frame carried thereby, this sub-frame enclosing and carrying the escapement mechanism. The use of such a sub-frame,

' whilst efiective in reducing the noise of the escapement mechanism, considerably complicates manufacture of the overall clockwork movement, and adds to the total cost of the clock, which must include both a main frame and a subsidiary frame.

Other proposals have been directed to providing a sound-damping annular packing around the edge of the clockwork movement; providing a main supporting plate of the clockwork movement in a sound-damping material; and mounting clockwork movement in a casing by the intermediary of sound-damping blocks. However, these proposals, whilst adding to the cost, do not fully sound-proof the clock.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS The single FIGURE of the accompanying drawings is a schematic cross-section through an embodiment of an alarm clock according to the invention, given by way of example.

DESCRIPTION OF THE PREFERRED EMBODIMENT The alarm clock shown comprises a clockwork movement 1 enclosed in a soundproof case including a main body portion 2 and a rear wall 3. The two parts of the case are made by; moulding an expanded plastic material with a substantially non-porous smooth outer surface and an elastic inner cellular structure formed by sponge-like pores which have good sound absorbing properties. Suitable materials are natural or synthetic rubber, polyvinyl chloride and polyurethane, although the latter two materials are to be preferred. The outer surfaces of both parts of the case, or simply the visible outer surface of the portion 2, may, if required, be coated with a second material either to increase the rigidity of the case or for decorative purposes.

The main body portion 2 is formed of a circular front .wall 2' with an elongate cylindrical central aperture 12 and a substantially cylindrical sidewall 2" extending rearwardly from the front wall. An assembly of coaxial pipes 13, 13 and a central shaft 14 fixed to the clockwork movement 1 protrude through the aperture 12, the inner pipe 13' and the shaft 14 being driven in conventional manner by the clockwork movement at a rate of one revolution per 12 hours and one revolution per hour respectively.

About the periphery of the front wall 2' is mounted a rigid ring 15, and adial 16 is secured to this ring 15 so as to cover the outer face of the front wall 2. The dial 16 has a circular central aperture 16' for the assembly of pipes 13, 13' and carries, at the periphery of its outer face, conventional hour and minute divisions.

A transparent disc 17 is securely fixed to the outer pipe 13, and carries thereon at least one reference mark, not shown. Outside this disc 17, hour and min utes hands 8 are mounted on the pipe 13' and the shaft 14 respectively so as to give, in cooperation with the divisions on the dial 16, an indication of time. A transparent cover 7 is fixed by means of an O-ring 9 onto the ring 15, this cover 7 including a shoulder 18 against which the periphery of disc 17 is rotatably mounted, and a central opening 18 for the shaft 14. An external knurled knob 19 is secured to the outer end of shaft 14 to permit setting of the hands 8.

The rear wall 3 fits against the clockwork movement 1 between the cylindrical inner surface of the side wall 2", said side wall 2" extending rearwardly of the wall 3 to form a rear recess 20 therewith. An opaque cover 6 of sound transmitting material is fitted in said side wall 2" to close the recess 20. A schematically shown sonorous alarm, including a gong 4 secured to the wall 3 by means of a screw 4' engaging in a threaded socket 4" embedded in the wall 3, a hammer 5 and a driving mechanism 21 for the hammer 5, is mounted in the recess 20. The cover 6 also carries at least one control member 10 for the alarm, said member 10 beingrotatably mounted on a shaft 10 passing through an aperture in the wall 3 and operatively connected to the clockwork movement 1. By means of this control member 10, the outer pipe 13 and disc 17 can be rotated to set the mark thereon to show the time at which the alarm mechanism is to be triggered. A second pushbutton control member 11 mounted in a recess in the wall 2" enables the alarm mechanism to be blocked, in a conventional manner. Other control members, for example for winding the alarm mechanism, may also be included.

It can be readily seen that during operation of the described alarm clock, the case 2 absorbs practically all of the sound of the clockwork movement 1, in particular that of the escapement mechanism. The sound of the alarm, however, is not appreciably attenuated. Moulding of the case enables the described clock to be manufactured at a relatively low cost price. The moulded case moreover has a good resistance to shocks and ensures a good protection of the clockwork movement against humidity, dust and atmospheric pollutions.

What is claimed is:

1. A clock comprising a clockwork movement, a substantially soundproof case of expanded plastic material enclosing said clockwork movement, said material having an inner cellular structure, a dial fixed outside said case, an elongate cylindrical aperture passing through said case and said dial, a coaxial pipe driving assembly driven by said clockwork movement, said assembly 3 passing through said aperture and protruding beyond said dial, and time indicating members drivably mounted on a part of said assembly protruding beyond said dial.

2. A clock according to claim 1, in which said case is made in two parts, a first part including a flat front wall and at least one side wall extending rearwardly therefrom, said front wall including said aperture and said dialbeing fixed adjacent to the outer face of said front wall, said at least one side wall surrounding and extending rearwardly beyond said clockwork movement, and a second part forming a rear wall of the case fitting against said clockwork movement between said at least one side wall, said at least one side wall extendsmooth surface coating. 

1. A clock comprising a clockwork movement, a substantially soundproof case of expanded plastic material enclosing said clockwork movement, said material having an inner cellular structure, a dial fixed outside said case, an elongate cylindrical aperture passing through said case and said dial, a coaxial pipe driving assembly driven by said clockwork movement, said assembly passing through said aperture and protruding beyond said dial, and time indicating members drivably mounted on a part of said assembly protruding beyond said dial.
 2. A clock according to claim 1, in which said case is made in two parts, a first part including a flat front wall and at least one side wall extending rearwardly therefrom, said front wall including said aperture and said dial being fixed adjacent to the Outer face of said front wall, said at least one side wall surrounding and extending rearwardly beyond said clockwork movement, and a second part forming a rear wall of the case fitting against said clockwork movement between said at least one side wall, said at least one side wall extending rearwardly beyond said rear wall to form a rear recess therewith, a sound-transmitting cover closing said rear recess, and a sonorous alarm mounted in said rear recess.
 3. A clock according to claim 1, in which said case is in expanded polyvinyl chloride having a sponge-like inner cellular structure with a substantially non-porous smooth surface coating.
 4. A clock according to claim 1, in which said case is in expanded polyurethane having a sponge-like inner cellular structure with a substantially non-porous smooth surface coating. 